Apparatus for locating collars and the like in well pipe



1... K. MOORE March 26, 1968 APPARATUS FOR LOCATING COLLARS AND THE LIKEIN WELL PIPE Filed Sept. 29, 1966 4 Sheets-Sheet l e d rm M 06 0 C 0T.

4 mmm ww m x z xwvm xx 3 M m & Z 1 :ii: 5,, .IA. 1

. m i a m i m mad W 1 Ac. 5 a 82/ 0 maw aw c 550A 3 C3 2 2 3%; 3 1i TIL;:M i 3 3 M ii, 22,? Q 3i 1 5/ K% V j... q i f 2 fim Z Li? A TTORNE )"SMarch 26, 1968 L. K. MOORE APPARATUS FOR LOCATING COLLARS AND THE LIKEIN WELL PIPE Filed Sept. 29, 1966 4 Sheets-Sheet 2 law/e002 Moore I NVEN TOR.

BY A K rand ATTORNE YS 1.. K. MOORE 3,374,735

APPARATUS FOR LOGATING COLLARS AND THE LIKE IN WELL PIPE March 26, 19684 Sheets-Sheet 3 Filed Sept. 29, 1966 IN VENTOR.

BY H034 4 HM A 14 TTORXE YS L. K. MOORE March 26, 1968 APPARATUS FORLOCATING COLLARS AND THE LIKE IN WELL PIPE m w mi l! 4 flag; Is 7" 7 WWw t 6 w s e r 0 M e n m W a 1 gal SAND

ABSTRACT OF THE DISCLOSURE An apparatus for locating collars or the likein a well pipe, and which may be used in conjunction with detonatorapparatus, wherein means are provided for multiple selective collarlocation in a single run of the apparatus in a well pipe by themanipulation of a wire line, whereby a plurality of collars at difierentelevations may be located by movement of the apparatus in either anupward or downward longitudinal direction in the well pipe and withoutrequiring electrical cables extending from the apparatus to the surfaceor a removal of the apparatus from the well pipe.

Briefly, this invention relates to a new and improved apparatus which isadapted to be actuated by a wire line on which the apparatus issupported for extending and retracting collar-engaging fingers and forlocating collars with such fingers when they are extended.

It is therefore an object of this invention to provide such anapparatus, which apparatus may be used for determining the elevation ofone or more collars in a well pipe and may be used for latching adetonator apparatus or other apparatus in the well pipe for actuatingsame or for any other purpose.

The preferred embodiment of this invention will be described hereinaftertogether with other features, and additional objects will become evidentfrom such description.

The invention will be more readily understood from a reading of thefollowing specification and by reference to the accompanying drawingsforming a part thereof, wherein an example of the invention is shown,and wherein:

FIG. 1 is an elevation, partly in section, of one form of the apparatusof this invention with its collar-engaging fingers in the retractedposition;

FIG. 2 is a view similar to FIG. 1, but illustrating the collar-engagingfingers in the extended position;

FIGS. 3A and 3B are elevational views, partly in section, illustratingthe upper and lower portions of another States atent "ice thecollar-engaging finger construction which may be used in the apparatusillustrated in FIGS. 3A and 3B.

In the drawings, the letter A designates generally the collar locatorapparatus illustrated in FIGS. 1 and 2 which is adapted to locate one ormore collars C in a well casing or pipe P, The apparatus A'may belowered ona flexible line L which may be a conventional slick wire lineor similar member. The apparatus A includes one 01 more collar-engagingfingers 10 which are adapted to be moved from a retracted position(FIG. 1) to an extended position (FIG. 2) by manipulation of the wireline L after the apparatus A is in the well pipe P. Also, thecollar-engaging fingers 10 may be moved from the extended position tothe retractedposition when the apparatus A is in the well pipe P,whereby the apparatus A may be moved either upwardly or downwardly inthe pipe P from one collar C to another with the finger or fingers 10 inthe retracted position.

Considering the form of the invention ilustrated in FIGS. 1 and 2 inmore detail, the apparatus A includes a mandrel or body 11 which isoperably connected t its upper end to the flexible line L. Preferably, aspecial connector 15 is threaded at threads 11a to the upper end of themandrel 11, with the wire line L suitably secured to the coupling 15 andextending thereabove to the surface of the well in which the pipe P islocated.

The lower end of the coupling 15 is formed with a depending annularextension 15a which has an internal surface 15b spaced outwardly fromthe external surface of the mandrel 11. An illustrated in the drawings,the collar-engaging finger or fingers 10* extend into the inner annularrecess thus provided by the extension 15a and are welded thereto asindicated at 15c, or are otherwise suitably attached to the coupling 15.It is to be noted that each of the collar engaging fingers 10 is formedof a relatively narrow strip of steel or other flexible material whichmay be bent from its normally straight shape (FIG. 1) to a curved orextended shape (FIG. 2) and subsequently returned to the straight shapeof FIG. 1.

A drag assembly D is mounted externally of the mandrel E11 and isprovidde with resilient bowed pring elements 20 for frictionallyengaging the inside of the casing form of the apparatus, respectively,wherein a detonator mechanism forms a part of the apparatus, andillustrating such apparatus with the collar-engaging finger in aretracted position; a

FIGS. 4A and 4B illustrate the intermediate and lower portions of theform of theapparatus shown in FIGS. 3A and 3B, but illustrating thecollar-engaging finger in the extended position;

FIG. 5 is a partial view taken on line 55 of FIG. 4A to illustrate asafety mechanism used in conjunction with the apparatus in one form ofthe invention; 1

FIG. 6 is a view of the apparatus of FIGS. 3A, 3B, 4A, and 4B after theapparatus has been used for detonating an explosive and is in a positionfor movement out of the well pipe;

or pipe P. In the form of the invention illustrated in FIGS. 1 and 2,the upper ends of the friction spring elements 20 are secured to aslidable ring 21 by welding or any other suitable means. Such ring 21fits slidably over a sleeve 22 which surrounds the mandrel 11 forlongitudinal relative movement with respect thereto. At the bottom ofthe curved portion of each flexible spring element 20, each of suchelements 20 is secured to the sleeve 22 by screws 23 which extendthrough a connecting ring 24 and into the sleeve 22 so that the flexiblespring elements 20 move with the sleeve 22, but the upper ends thereofwhich are secured to the ring 21 may move relative to the sleeve 22 upona contraction or expansion of the spring elements 20 in a lateraldirection. A spring 28 or other resilient means is confined between theslidable ring 21 and a fixed ring. 30 which is secured to the sleeve 22by one or more retaining screws 31. Such coil spring 28 serves tomaintain a longitudinal force on the ring "21 to thereby maintain theflexible spring elements 20 in an expanded position for constantfrictional engagement with FIG. 7 is a partial view illustrating amodification of t the apparatus of FIGS. 3A and 3B wherein the detonatorportion of the apparatus is replaced by a wire-line coupling directly tothe collar engaging portion of the appara-' tus; and

FIG. 8 is a partial view illustrating a modification. of

suificiently large diameter to allow outward expansion of the elements20 into frictional contact with the inside of the pipe P.

At the upper end of the sleeve 22, an expander 35 having a generallyexternal cone shape on the surface 35a is provided. Such expander 35, aswill be more evident hereinafter, serves to urge the collar-engagingfingers from the retracted position of FIG. 1 to the extended positionof FIG. 2 upon a relative longitudinal movement between the mandrel 11and the drag assembly D.

For controlling the relative movement between the mandrel 11 and thedrag assembly D, the mandrel 11 is provided with a control slot which isgenerally designated with the numeral 33, which control slot 33 isadapted to receive a pin or rod 34 therein for relative movement. Thepin or rod 34 is not connected to the mandrel 11 or any part of the slot33 but is secured to a control sleeve 36 on the inner bore 34a thereof.,The sleeve 36 is disposed below the sleeve 22 and above a retainingelement 38 which is welded or otherwise secured to the lower ends of theflexible friction elements 20. The retainer element 38 preferably isformed with an enlarged internal bore and threads 38a therein forconnecting to any suitable tool which is suspended therebelow, such as aconventional detonator apparatus or the like. It is also-to be notedthat the mandrel 11 has lower internal threads 11b which may also beconnected to a tool or some part thereof for operation in conjunctionwith the apparatus A, if so desired.

The control slot 33 is formed with a short portion 33a and a longportion 33b. In the position of the apparatus A illustrated in thedrawings, the long portion 33b is connected with the short portion 33aof the control slot 33 by a lower laterally extending inclined slotportion 330. An intermediate longitudinal slot portion 33d is alsoprovided, as well as an intermediate laterally extending inclined slot33e, the purpose of which will be more evident so that the mandrel 11moves downwardly with respect to the drag assembly D, causing the longerslot portion 33b to move downwardly with respect to the control pin 34,during which movement the control pin 34 is .guided by engagement withthe guide wall 33 so that it moves upwardly and ultimately reaches theupper or terminal end of the longer slot portion 33b (FIG. 2). Duringsuch downward movement of the mandrel 1'1 with respect to the dragassembly D and the control pin 34, the expander cone 35 is engaged bythe collar-engaging fingers 10 to urge the fingers 10 to an extendedposition and ultimately reaching the fully extended position shown inFIG. 2.

If the collar-engaging fingers -10 are not adjacent a collar such as thecollar C shown in drawings, the entire apparatus A moves downwardly inthe pipe P after the pin 34 hasreached the upper end of the slot 33buntil the fingers 10 do extend into the internal recess or groove of thecollar C. Due to the decrease in the weight or load on the line L whenthe fingers .10 rest in the collar C, the operator is informed at thesurface that this position has been reached. The elevation of theparticular collar C thus engaged by the fingers 10 can be readilymeasured by determining the length of the flexible line L which is inthe pipe P, 'using any conventional measuring equipment.

hereinafter. Also of significance in connection with the control slot 33are guide wall surfaces 33f, 33g, and 33h, all of which serve to guidethe movements of the control pin 34, as will be explained.

In the operation or use of the apparatus A of this invention, it islowered into the well pipe or casing P on the flexible line L, with thecontrol pin 34in the upper or terminal end of the control guide slotportion 33a (FIG. 1). The weight of the apparatus A is itself sufficientto force the apparatus A to fall by gravity, with the friction springsor elements 20 frictionally engaging the inside of the pipe P andtending to resist such downward movement. In the event the apparatus Ais not of itself sufficiently heavy to cause the apparatus A to fall bygravity, additional weight may be included above'the apparatus A ortherebelow in order to move the apparatus A downwardly in the pipe P onthe flexible line L. In any event, the apparatus A is caused to movedownwardly by gravity, and the friction of the drag springs or elements20 on the inside of the pipe P maintains the control pin 34 in the upperor terminal end of the slot portion 33a. When the control pin 34 is insuch position, the collar-engaging fingers 10 are in the substantiallystraight or retracted position illustrated in FIG. 1. When the apparatusA is approximately at the elevation desired for locating a particularcollar C in the pipe P, the operator lifts upwardly on the wire line Lto impart an upward movement to the mandrel 11. The drag assembly Dremains stationary in the pipe P as the mandrel 11 moves upwardlyrelative thereto, and therefore the control slot 33 moves upwardly withrespect to the control pin 34. When the mandrel 11 has been raisedsufliciently to position the pin 34 at the lower end of the short slotportion 33a, the continued upward movement of the mandrel 11 imparts arotation to the sleeve 36 as the pin 34 moves laterally in the slotportion 33c'to the lower end of the longer slot portion 33b.

The operator at the surface of the well can determine when the pin 34 isat the lower end of the slot portion 33b because at that time the dragassembly D will also begin to move and therefore increased resistance tothe upward movement will occur.

Thereafter, the operator slacks off on the wire line L The apparatus Amay thereafter be moved to another collar within the well pipe P or itmay be removed entirely from the pipe P if so desired. To reset the toolwith the fingers 10 in the retracted position to accomplish suchmovement of the apparatus A within the pipe P, the operator liftsupwardly on the wire line L so as to cause the mandrel 11 to moveupwardly with respect to the drag assembly D and to simultaneously causethe relative upward movement of the slot portion 33b with respect to thecontrol pin 34. When the pin reaches the surface 33g, it is guided intothe intermediate longitudinal slot portion 33d, which is indicated tothe operator by the increased weight of the apparatus when the dragassembly D begins to move withthe mandrel 11. At that time, the operatorslacks oil again on the wire line L, causing the downward movement ofthe mandrel 11 and the slot 33 with respect to the control pin 34 andultimately causing a contact between the pin 34 and the guide wallsurface 33h which causes a relative movement of the groove 33e withrespect to the pin 34 and a guiding of the pin 34 to the upper end ofthe short slot portion 33a. When the pin 34 reaches the upper orterminal portion of the slot portion 33a (FIG. 1), the fingers 10 are inthe retracted position since the mandrel 11 has been moved downwardlywith respect to the fingers 10 to that position shown in FIG. 1. Theapparatus A may then be moved'to any other location in the pipe P, or itcan be removed completely from the pipe P with the fingers 10 intheretracted position. When the apparatus A is just above the nextcollar C to be located, the above steps for causing the fingers 10 tomove to the extended position are repeated, as will be understood.

The form of the invention illustrated in FIGS. 1 and 2 may be operatedin an upside down position from that illustrated in FIGS. 1 and 2, inwhich case the flexible line L is connected to the mandrel 11 at or inthe vicinity of the thread 11b, which end is at that time at the upperposition. When the apparatus A is operated in such an upside downposition, the apparatus A is lowered into the pipe P with the pin 34 inthe control slot 33 at the junction between the long slot 33b and theinclined slot 33c. In such position, the fingers 10 are in the retractedposition of FIG. 1 as viewed from an upside down posi tion. Therefore,when it is desired to move the fingers 10 to an extended position, theoperator simply picks up with the wire line L, and the relative movementof the mandrel 11 with respect to drag springs D causes the slot 33b tomove relative to the pin 34 until the pin 34 reaches the terminalend ofthe slot 33b, which is the upper end thereof as viewed in FIG. 1, but itthe lower end in the upside down position. This corresponds to theposition shown in FIG. 2, and-therefore the fingers are thus expanded tothe extended position shown in FIG. 2 but, of course, are extendedupwardly when in the upside down position. Therefore, the continuedupward movement of the wire line L moves the extended fingers 10 intothe collar C next above such fingers 10. When the fingers 10 move intothe collar C, the increased resistance to movement is indicated to theoperator so that he knows that this has occurred and he can thendetermine the eleva tion of the collar C by the length of the wire lineL in the pipe P, as previously explained.

To release the fingers 10 and move them to the retracted position ofFIG. 1, the wire line L is slacked off so that the pin 34 reaches theposition of the intermediate slot 33d, then the wire line is picked upand'moved to the terminal end of the short portion 33a as indicated inFIG. 1. A continued picking up on the line L will thus move the entireapparatus A out of the well if this is desired.

In FIGS. 3A and 3B, an apparatus A1 is illustrated which is another formof the present invention which is particularly adapted for use inconjunction with a detonator or firing apparatus F, one example of whichis illustrated in United States Patent No. 3,180,261. The apparatus A1is adapted to be lowered and raised in a casing or pipe P having acollar C therein by means of a flexible line L.

The apparatus A1 includes a mandrel 111 which is suitably connected atits upper end, preferably with threads 111a to the housing 40 of thedetonator unit F. The housing 40 isconnected to the flexible line orwire line L so that such line L is operably connected to the mandrel111.

The mandrel 111 is in the form of a tube or pipe with a bore 111!)through which a firing rod 41 extends. The upper end of the firing rod41 has a threaded box 41a into which is threaded the lower end of anactuator rod 42 which extends upwardly into the housing or body 40 andforms a part of the firing unit F as will be explained more in detail.

Although the firing mechanism or unit F may take several forms, one ofwhich is illustrated in said United States'Patent No. 3,180,261, theform shown in the drawings includes a piston 43 mounted on the actuatingrod 42 and movable therewith, through which a restricted orifice 43a isprovided so that upon relative movement between the rod 42 and thehousing 40 fluid 44 within the housing 40 and below a floating seal 45is caused to move from one side of thepiston 43 to the other through therestricted opening 43a. The piston 43 has closely associated therewith apair of electrical contacts 46a and 46b which are not electricallyconnected together but which become electrically connected together bymeans ofan electrical ring 47 when the contacts 461: and 46b engage thecontact ring 47, thereby completing an electrical circuit from a batterysource 48 downwardly through the firing unit F -by means of anelectrical wire 49 which extends downwardly through the firing rod 41and is connected to an explosive E (FIG. 3B).

Normally, the actuating rod 42 is held in an upper or raised position bymeans of a coil spring 50 which acts upon a shoulder 42a on theactuating rod 42, but when the actuating rod 42 and the firing rod 41are held to prevent them from moving upwardly, an upward movement of thehousing 40 causes a relative movement of the contacts 46a and 46btowards the contact ring 47 to bring them into engagement and to therebyclose the electrical circuit from the battery 48 to the explosive E,whereby detonation of the explosive E occurs.

The mandrel 111 is formed with a slotted portion or slot 33 which isidentical with the slot 33 of FIG. 1, except that it is upside down ascompared to FIG. 1. Therefore, the parts of the slot 33 in FIG. 3A bearthe same numeral and letter designations as the parts of the slots 33 inFIG. 1. Similarly, thecontrol pin 34 of FIG.

3A is mounted in a manner similar to that of FIG. 1 since it is notconnected to the mandrel 111 but extends from and is a part of the ring36. The operation of the control pin 34 within the slot 33 of FIG. 3Awill be explained hereinafter.

A drag assembly D-l which is shown in FIGS. 3A and 3B is similar to thedrag assembly I) of FIGS. 1 and 2 except that it is upside down and hasother modifications as will be explained. Such assembly D-1 includes asleeve 122 which has a coupling 55 secured thereto by threading or othermeans at its upper end. The drag assembly D1 has flexible drag springsor friction elements which correspond with the elements 20 of FIG. 1 andwhich are connected at their upper ends to the coupling 55 by rivets,welding, or other suitable means. The lower ends of the frictionelements 120 are connected to a sliding ring 121 by welding, rivets, orother suitable means so that the lower ends of the friction elements 120are free to move relative to the sleeve 122. A coil spring 128 isdisposed between the ring 121 and another ring 130 which is secured onthe sleeve 122 by means of screws 121 or other suitable securing means.Such coil spring 128 serves to maintain the friction elements 120 infrictional engagement with the inside of the well pipe P at all times,while allowing a collapse or reduction in diameter of the springs 120for smaller sizes of pipe if this is desired or if the springs 120 passthrough a smaller section of pipe in use.

The coupling 55 has a connector tube 56 welded or otherwise securedthereto and which extends upwardly so as to generally surround themandrel 111. The upper end of the connector tube 56 is welded orotherwise connected to a retaining collar 138 so as to provide aconfined space for the ring 36 to move rotationally with respectthereto, while limiting the relative longitudinal movement between thering 36 and the drag assembly D1. It is to be noted that the connectingsleeve 56 has an upper flange 56a which forms the lower support for thering 36. Also, the sleeve 56 has a lower flange 56b which is adapted tobe engaged by a lower shoulder 111d of the mandrel 111 for transmittingdownward forces to the drag springs D-1 and the parts therebelow, ifdesired, in the lowering of the apparatus A1 in the pipe P.

An explosive support body 60 is connected to the lower end of the firingrod 41 by threads or other suitable means, and such body 60 is providedwith a passage or opening 60a through which the electrical wire 49passes to the explosive E. The explosive E is mounted in any suitablemanner on the external surface of the body 60, preferably with a pair ofdeflectors 60b on each side of the explosive E to direct the explosiveforce when the explosive E is detonated.

A latch finger 110 is mounted on a bracket 110a for movement therewith,which bracket is pivoted at a pivot pin 11012 disposed on an extensionor arm 600 of the body 60. The bracket 110a has a notch or other similarconfiguration 1100 which is engaged by a leaf spring 62 secured to thebody 60 by a screw 62a or other suitable means so that the bracket 110aand the latch finger 110 therewith are urged from a substantiallyvertical position to an inclined or extended position, as will be morefully explained.

The latch 110 is held in a retracted position (FIG. 3B) in opposition tothe force of the spring 62 by means of a coil spring 63 or other similarresilient means which acts between the upper end of the body 60 and arelease ring 64. The release ring 64 is connected to a latch rod 65which extends downwardly through a guide tube 60d mounted on the body 60and is pivotally connected at its lower end to a link 66 which in turnis pivotally connected to the bracket 110a. A guide rod 65acorresponding to the rod 65 but on the opposite side thereof is alsoconnected to the release ring 64, and it extends downwardly through aring 6% on the body 60 for serving to stabilize the movement of therelease ring 64 with respect to. the firing rod 41, as will be moreevident hereinafter. In any event, when the spring' 63 is in theextended position illustrated in FIG. 3B, it exerts an upward force onthe ring 64 and thereby on the rod 65 to hold the bracket 110a and thelatch finger 110 in the upwardly extending retracted position inopposition to the force of the spring 62. However, when the release ring64 is moved downwardly with respect to the body 60 compressing thespring 63, the force of the spring 62 then acts to take up the slackprovided by such compression of the spring 63 and move the finger 110outwardly to the extended position which is shown in FIG. 4B of thedrawmgs.

In the operation or use of the form of the invention illustrated inFIGS. 3A, 3B, 4A, and 4B, the apparatus is run into the well pipe P withthe parts in the positions illustrated in FIGS. 3A and 3B. The weight ofthe tool or any supplemental weight disposed thereabove acts to urge theapparatus A-1 downwardly in the well by gravity, with the springassembly D-1 dragging on the inside surface of the pipe P. The controlpin 34 is thus held at or near the top of the long portion 33b of theslot 33 as illustrated in FIG.- 3A. To prevent an overloading of the pin34 by the weight of the apparatus during the lowering thereof, the pin34 may be spaced slightly below the wall of the slot when in theposition shown in FIG. 3A and the weight may be transmitted through thecontact of the shoulder 111d and the flange 56b or any other suitableshoulder contact.

When the apparatus A-1 has been lowered to a position at which it isdesired to release the latch finger 110 to an extended position, theoperator picks upwardly on the flexible line L at the surface of thewell to thereby raise the body 40 and the mandrel 111 with respect tothe drag assembly D-1. The coil spring 50 maintains the actuator rod 42in the upper position shown in FIG. 3A during such initial liftingmovement, and therefore the rod 41 likewise maintains its same relativeposition with respect to the mandrel 111 during the initial liftingmovement. The firing rod 41 is thus moved upwardly with respect to thesleeve 122 so as to bring the release ring 64 into engagement with theshoulder at the lower end 122a of the sleeve 122. Continued upwardmovement of the wire line L then compresses the spring 63 and urges therod 65 downwardly with respect to the body 60 to release the holdingforce which was holding the latch finger 110' in the retracted positionand thereby allowing the spring force of the leaf spring 62 to take overand urge the finger 110 outwardly to the extended position of FIG. 4B.The upward movement of the apparatus A1 continues even after the finger110 is moved to its extended position until the finger 110 engages in acollar C as shown in FIG. 4B, at which time the firing rod 41 and theactuator rod 42 are latched into the Well pipe P through the latchfinger- 110. The increased weight or resistance offered at the surfaceof the well indicates to the operator that the latch finger 110 hasengaged the collar C, and if firing of the explosive E is not desired, ameasurement as to the elevation of the collar C may be obtained.However, if firing of the explosive E is desired, it is to be noted thatthe explosive E is disposed at the collar C in which the finger 110 isdisposed. This is particularly suitable when using the explosive E forproviding the explosive force in conjunction with a torque on the pipe Pfor backing off or unthreading a collar such as the collar C.

To fire the explosive E after the finger 110 has engaged the recess orinternal opening of the collar C, the operator continues to pullupwardly on the wire line L. It is to be noted from FIG. 4A that at thetime the latch finger 110 is engaged in the collar C and prior to theany relative movement between the housing 40 and the rod 42, the controlpin 34 has moved to the bottom or terminal end of the slot 33b or atsome point near such lower end. Preferably, pin 34 does not engage thelower wall of the slot 33b, but instead, the shoulder 111d engages theflange 56a of the connector sleeve 56 so that the subsequent lift- 8.ing force is transmitted to the drag assembly D-1 through suchengagement. Therefore, after the finger 110 is engaged in the collar C,the continued upward movement of the wire line L imparts a lifting onthe housing 40, the mandrel 111, and the entire drag assembly D-l. Thefiring rod 41, the actuator rod 42, and the body 60 are all preventedfrom moving upwardly because of the latching of the finger 110' in thecollar C. Since the firing mechanism or unit F has the restriction 43ain the piston 43, a time delay is provided before the engagement of theelectrical contacts 46a and 46b with the contact ring 47, and thereforea time delay is provided before the firing of the explosive E.

It should be noted that during the movement of the drag assembly D-1upwardly with the mandrel 111 and the housing 40, the lower end 122amoves upwardly with respect to the release ring 64 so that the releasering 64 is spaced therefrom substantially as shown in FIG; 6, whichmeans that the latch finger 110 could return to the retracted positionexcept for the force which is being exerted upwardly thereon through therod 41 by the pulling action on the wire line L. Thus, the finger 110remains in the collar C during the upward pull on the 'wire line L anduntil the firing of the explosive takes place. However, immediately uponthe firing of the explosive E, the operator may release the pullingforce on the wire line L and thereby enable the compressed spring 63 tourge the finger 110 toward the body 60 and out of the collar C to thusreturn it to the retracted position of FIG. 3B.

It should be noted that if firing is not desired, the finger 110 mayalso be retracted to the retracted position by a slacking off of thewire line L so that the control pin 34 moves first to the intermediateslot 33d and then by picking up on the line L, the pin 34 is guidedthrough the inclined slot 33:: to the short slot portion 330. Then, byslacking off again on the line A, the mandrel 111 moves relatively withrespect to the pin 34 so as to return the pin 34 to the top of the longslot portion 33b as shown in FIG. 3A. As can be appreciated, repeatedmanipulations with the wire line L may be utilized for retracting andextending'the latch finger 110 as desired within the pipe P so that anumber of collars C may be located with: out removing the apparatus fromthe pipe P.

In FIG. 5, a detailed partial sectional view taken on line 5-5 of FIG.4A illustrates a safety mechanism which is preferably incorporated withthe apparatus of FIGS. 3A, 3B, 4A, and 4B. The mandrel 111 is providedwith a longitudinal opening 111:; and a resilient safety latch mountedin proximity to such opening 111e. The lower end of the safety latch 80is connected to the mandrel 111 by a screw 80c or other suitablesecuring means. The upper end of the safety latch 80 preferably has anenlarged head 80a with a curved inner surface 80b, which head is adaptedto move laterally as will be explained. A stop shoulder or collar 41b isformed integrally with or secured to the firing rod 41 for movementtherewith longitudinally relative to the mandrel 111. The head 80a ofthe safety latch extends into the bore of the mandrel 111 a sufficientdistance to prevent the movement of the head 80:: longitudinallyupwardly past the shoulder 41b until such time as the head 80a haspassed upwardly above the upper end of the retaining collar 138, whichposition is illustrated in FIG. 5. Therefore, so long as the head 80a isconfined within the sleeve 36, the head 80a cannot pass upwardly withrespect to such collar 41b. Such safety latch prevents the relativemovement of the mandrel 111 upwardly with respect to the firing rod 41and therefore prevents the relativemovement between the housing 40 andthe actuator rod 42 to thereby prevent a closing of the electricalcircuit by the contacts 46a, 46b, and 47 unless the apparatus has beenmoved to its extended posi-- tion as shown in FIGS. 4A and 4B. Suchposition cannot be reached until the latch finger has been fullyextended and is engaged in a collar C, and therefore the firingmechanism F cannot be actuated until the latch finger 110 is in thecollar C and the tool is otherwise ready for firing. Such safetymechanism prevents an inadvertent firing in case the body 60 in thevicinity of the explosive E is caught or stuck in the well pipe bydebris or other foreign object at a position wherein it is undesirabletofire the explosive E. Also, if the latch finger 110 inadvertentlybecomes disconnected from the rod 65 and therefore inadvertently movesto the extended position so as to become engaged in the collar C when itis not desired to fire the mechanism, the safety mechanism of FIG. 'willprevent a firing because it prevents enough relative movementbetween'the rod 42 and the housing 40 to allow a movement of theelectrical contacts 46a, 46b, and the ring 47 into engagement with eachother even though an upward pull is exerted on the wire line L.

In FIG. 7, another modification of the invention is illustrated whereinthe apparatus of FIGS. 3A, 3B, 4A, and 4B is modified by providing withthe apparatus A1 a connector head H (FIG. 7) which takes the place ofthe firing unit F of FIG. 3A. The upper end of the mandrel 111 isconnected to the connector head H at threads 111a, and the upper end ofthe head H is connected to a conventional rope socket 85 having theflexible line L attached thereabove. The connector head H preferably hasan internal rod 86 integral therewith or secured thereto which has malethreads 86a adapted to be threaded into the threaded box 41a of thefiring rod 41.

In the form of'the invention shown in FIG. 7, the detonator apparatus orunit F is thus replaced with the connector head H so that the apparatusA-l is not used for detonating an explosive, but is used solely forlocating collars in the pipe P. The operation is identical in the formof the invention of FIG. 7, except that the operation stops insofar asFIG. 3A is concerned after the latch finger 110 has engaged the collarC. At that time, the operator at the surface can determine the elevationof the collar C and may thereafter release the latch finger 110 byslacking off on the wire line L as previously described in connectionwith FIGS. 3A, 3B, 4A, and 4B.

In FIG. 8, a further modification is illustrated wherein a pair of latchfingers 110 is mounted on the body 160. The body 160 is identical tothat illustrated as the body 60 in FIGS. 3B and 4B except that theexplosive E is not mounted at the same elevation as the fingers 110.Instead, the body 160 has a threaded connection at 1602 to a tubularsupport 88 upon which an explosive E-1 is mounted. Such explosive E-lmay be a perforator or jet cutter or other type of conventionalexplosive which is detonated upon the closing of the contacts 46a, 46b,and the electrical ring 47 as described previously with respect to FIGS.3A, 3B, 4A, and 4B.

The latch fingers 110 in FIG. 8 posite sides of the body at pivot pin11% with a are disposed on op- 160 and are pivotally mounted spring 162secured to each latch bracket 110a and to the body 160 for urging thebrackets 110a and the fingers 110 therewith to the extended positionshown in FIG. 8. However, the coil spring 63 serves to hold the releasecollar 64 in the upper position so that the operating rod 65 for each ofthe latch fingers 110 holds each latch finger 110 in the retractedposition corresponding to that shown in FIG. 3B until the release collar64 is urged downwardly in the manner previously described in connectionwith FIGS. 3A, 3B, 4A. and 4B.

Thus, when the form of the invention of FIG. 8 is utilized, the fingers110 are in the retracted position when lowering the apparatus A1 intothe well pipe P, but when it is desired to move the fingers 110 'to theextended position shown in FIG. 8, the wire line L is manipulated bylifting upwardly on same to force the release collar 64 downwardly bythe engagement with the lower end 122a of the sleeve 122, where-by thelatch fingers 110 are urged to the extended position by the springs 162in essentially the same manner as described heretofore in connectionwith FIGS. 3A, 3B, 4A, and 4B.

.T he foregoing disclosure and description of the invention areillustrative and explanatory thereof, and various changes in the size,shape, and materials as well as in the details of the illustratedconstruction may be made within the scope of the appended claims withoutdeparting from the spirit of the invention.

What is claimed is:

1. An apparatus for locating collars or the like in a well pipe,comprising:

(a) a mandrel;

(b) a flexible line operably connected to said mandrel for raising andlowering same in a well pipe;

(c) a drag assembly adapted to frictionally engage the inside of thepipe and mounted externally of said mandrel for limited relativelongitudinal movement;

(d) a collar-engaging finger supported by said mandrel;

(e) means for moving said finger to and from a re tractedposition and toand from an extended position by a manipulation of the flexible line andpredetermined relative longitudinal movement between said mandrel andsaid drag assembly; and

(f) said finger being capable of longitudinally passing a collar in awell pipe when moving in both longitudinal directions when in theretracted position but being engageable with such a collar when in theextended position.

2. The structure set forth in claim 1, including:

(a) said mandrel having a control slot with a long portion, a shortportion, and an intermediate portion connecting the'long and shortportions; and

(b) said drag assembly having a pin therewith and extending into saidcontrol slot for movement to the long portion or the short portion forcontrolling the position of the drag assembly with respect to themandrel upon a manipulation of the flexible line.

3. The structure set forth in claim 1, including:

(a) a detonator apparatus having a firing rod therewith;

(b) means connecting said detonator apparatus to said mandrel with saidfiring rod extending therethrough; and

(c) means connecting said collar-engaging finger to said firing rod.

4. The structure set forth in claim 1, including:

(a) a detonator apparatus having a firing rod therewith;

(b) means connecting said detonator apparatus to said mandrel with saidfiring rod extending therethrough;

(c) means connecting said collar-engaging finger to said firing rod; and

(d) an explosive supported by the firing rod at substantially the sameelevation as the collar-engaging finger.

5. The structure set forth in claim 1, including:

(a) a detonator apparatus having a firing rod therewith;

(b) means connecting said detonator apparatus to said mandrel with saidfiring rod extending therethrough;

(c) means connecting said collar-engaging finger to said firing rod; and

(d) an explosive supported by the firing rod below the collar-engagingfinger.

6. The structure set forth in claim 1, including:

(a) means for releasably holding said collar-engaging finger in theretracted position; and

(b) means for urging said finger to the extended position upon apredetermined longitudinal movement of said mandrel relative to saiddrag assembly.

7. The structure set forth in claim 1, including:

(a) said mandrel having a control slot with a long portion, a shortportion, and an intermediate portion connecting the long and shortportions;

(b) said drag assembly having a pin therewith and extending into saidcontrol slot for movement to the long portion or the short portion forcontrolling the position of the drag assembly withrespe'ct to themandrel upon a manipulation of the fiexible line; (c) means forreleasably holding said collar-engaging finger in the retracted positionwhen said pin is at a point near one end of said short portion of saidcontrol slot; and v I (d) means for urging said finger to the extendedposition when said pin has moved in said Control slot to a point nearone end of said long portion ofthe slot.

The structure set forth'in claim 1-, including: I h (a) a detonatorapparatus having a firing rod therewith;

'(b) means connecting said detonator apparatus to said mandrel with'saidfiring rod extending therethrough;

' (a) a detonator apparatus having a firing rod therewith; (b) meansconnecting said detonator apparatus to said mandrel with said firing rodextending therethrough; (c) means connecting said collar-engaging fingerto said firing rod;

(d) a sleeve with sai drag 'a'ss' jernbl'y andsurrounding s and ki 4.(er) a safety latch mounted on said mandrel and disposed within s aidisleeve until said mandrel has been [moved relative to said jdragassembly for'moving said finger to an extended position; and y g I (f) astop shoulder on said firing rod engageab-le'with said safety latch toprevent relative: movement between said mandrel 'arid said firing roduntil said safety latch has moved outof said. sleeve. I 1 0. Thestructure set iorth inclaim i, including:

(a) said finger being resiliently urged to theretracted c i om I (b)-expander means for urging said finger outwardly to the extendedposition. 1 4.

v V f References Cited-- UNITED STATES PATENTS 25 BENJAMINBORCHELT,'Primary Examiner,

SAMUEL .w. ENGLE, Examiner. V. R. PENDEGRA'SS, Assistant Examiner.

